EEG Non-Epileptiform Abnormalities 2

Question 1

Focal polymorphic delta activity (PDA) over the right temporal region in an awake adult most strongly suggests:

Accepted Answer

A structural lesion in the right temporal area

Answer

Normal drowsiness

Answer

Generalized metabolic encephalopathy

Answer

Medication effect from benzodiazepines

Question 2

Generalized background slowing with intermittent frontal rhythmic delta activity (FIRDA) in an adult typically indicates:

Accepted Answer

Diffuse encephalopathy or deep midline dysfunction

Answer

Focal frontal lobe epilepsy

Answer

Normal aging changes

Answer

Posterior fossa tumor

Question 3

An asymmetry in the posterior dominant rhythm amplitude, with the right side consistently 50% lower than the left, suggests:

Accepted Answer

Possible structural or functional abnormality of the right hemisphere

Answer

Normal variant — mild asymmetry is always benign

Answer

Left hemisphere hyperexcitability indicating seizure focus

Answer

Electrode application error only

Question 4

Generalized voltage attenuation (low-voltage EEG) with amplitudes below 20 µV throughout may be caused by:

Accepted Answer

Scalp edema, subdural fluid, or certain medications such as barbiturates

Answer

Caffeine ingestion in the last hour

Answer

Hyperventilation artifact

Answer

Photic driving response

Question 5

Excessive beta activity (above 25 µV) generalized across the recording is most commonly associated with:

Accepted Answer

Sedative or anxiolytic medication use such as benzodiazepines

Answer

Temporal lobe epilepsy

Answer

Posterior fossa tumor

Answer

Normal hyperventilation response

Question 6

What does the term 'electrocerebral inactivity' (ECI) refer to in EEG?

Accepted Answer

Absence of cerebral electrical activity above 2 µV at maximum sensitivity, used as an adjunct in brain death determination

Answer

Normal low-voltage pattern during deep sleep

Answer

Background slowing to theta range

Answer

Intermittent suppression during burst-suppression pattern